Symptoms
Microsoft Unified Communications Web API (UCWA) may crash in a Microsoft Lync Server 2013 environment.
In addition, the following event is logged on the Lync Server 2013 Front End server:
Log Name: Lync Server Source: LS UCWA Date: Date/Time Event ID: 20003 Task Category: (1099) Level: Error Keywords: Classic User: N/A Computer: ServerName Description: UCWA encountered an unhandled exception. Exception: System.ArgumentException: The string argument value is invalid: 'panoramic-video' Parameter name: settings.AvailableMediaTypes at Microsoft.Rtc.Signaling.ArgumentVerifier.ThrowOnNullEmptyOrInvalidStringInCollectionCore(IEnumerable`1 collection, String paramName, Predicate`1 isValid) at Microsoft.Rtc.Collaboration.ConferenceInvitation..ctor(Conversation conversation, ConferenceInvitationSettings settings) at Microsoft.Rtc.Internal.Ucwa.Communication.ServiceConversation.AddSipUserAsync(ServiceInvitation serviceInvitation) at Microsoft.Rtc.Internal.Ucwa.Communication.ServiceConversation.AddUserAsync(ServiceInvitation serviceInvitation) at Microsoft.Rtc.Internal.Ucwa.Communication.ServiceConversation.AddUser(ServiceInvitation serviceInvitation) at Microsoft.Rtc.Internal.Ucwa.Communication.ServiceConversationManager.AddUserOrCall(String primaryServiceConversationId, InvitationResource invitationResource, InvitationType invitationType) at Microsoft.Rtc.Internal.Ucwa.Web.ParticipantInvitationsController.PostAddParticipantInvitation(ApplicationInstance application, InvitationContextQueryParameters invitationContext, AddParticipantInvitationInput addParticipantInvitationInput) at lambda_method(Closure , Object , Object[] ) at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass13.<GetExecutor>b__c(Object instance, Object[] methodParameters) at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments) at System.Threading.Tasks.TaskHelpers.RunSynchronously[TResult](Func`1 func, CancellationToken cancellationToken) Cause: An unhandled exception happened. Resolution: Restart the server. If the problem persists contact product support.
Resolution
To fix this issue, install the July 2017 cumulative update 5.0.8308.992 for the Lync Server 2013, Web Components Server.
